Lighted arrow boards are used for many purposes, including, for example to direct traffic and convey information to the public. Typically, an arrow board comprises about 15-25 light assemblies or heads spaced across the surface of a panel in a pattern that can be used to generate arrows, diamonds, chevrons, and other patterns based on the number and position of lights that are active at once. In order to enhance daytime visibility and to direct the light pattern in a desired direction, the lights are usually positioned within tube-shaped hoods. A light source such as a bulb or light emitting diodes (LEDs) is connected within the light head behind a protective lens or transparent cover.
Construction of conventional arrow boards is time-consuming work. Each of the hoods of the light heads are mounted to the board by screws or other similar fasteners with 3-4 screws per hood. Thus, with a 25-light arrow board and 4 screws per hood, 200 screws must be installed, so a significant expense of labor and time for construction is incurred on each arrow board.
While modern arrow boards use efficient LEDs as a light source, the low individual light output of single LEDs often causes manufacturers to have to implement 10-20 LEDs per light head in order to produce the required brightness for day and night viewing. With such a large number of LEDs, the light heads have electronic inefficiencies and extra costs due to high component counts and electronic losses.
Controllers for the arrow boards also have undesirable drawbacks. Usually, a controller uses mechanical switches for changing modes and the on/off functions of the board. Mechanical switches are expensive and prone to failure after extended use and exposure to the environment. The size of the switches also increases the bulkiness of the controller. Additionally, controllers usually lack sufficient protection from shorts and faults.
There is therefore a need for improvements in lighted arrow boards and the light head assemblies used for directional lighting in general.